Draft appliance



May 4, 1943.

T; F. DWYER, JR., E1- AL 2,318,472 y DRAFT APPLIANCE l Filed March 20, 1941 mmmawyar aw' Wr?? VENTORS I NEYv Patented May 4, 1943 Thomas Francis Dwyer, Jr.,

David W. Gray, Everett, Mass., Fabreeka Products Company.' Inc.,

Cambridge, and assgnors to Boston,

Mass., a corporation of Massachusetts Application March 20, 1941, Serial No. 384,258

s claims. (01.213440) v, Ihis invention relates to railroad draft gear and has for an object to provide a cushioning device between one or both abutments for taking draft and buffing thrusts of the draft yoke and coupler.

`'Another object is to provide a draft gear better able to withstand the shocks incident to present day conditions in high speed and braking.

VA further object is to provide such a device in which the play or movement longitudinally of the train is a. minimum, whereby the slack may be eliminated in a train as rapidly as possible.

Referring t the drawing Fig.` 1 shows one embodiment of this invention located in place to take the draft shocks. `Fig. 2 is a top plan view partly in section of a device for absorbing shocks.

Fig. 3 is a section on the line 3-#3 of Fig. 2.

Fig. 4 is a top plan view of another embodiment of this invention for the same purpose as that in Fig. 2.

Fig. is a section on the line 5-5 of Fig. 4.

Fig. 6 is a section on the line 6-6 of Fig. 4.

The usual co-upler I0 has a customary yoke Il connected thereto, and secured to the car frame in the usual manner is an abutment l2 against which the draft forces are transmitted. The corresponding abutment I3 takes care of buffer stresses. a xed draft pocket or housing in which the draft gear is adapted to be moved by the yoke. An appropriate shock absorbing pad I4 may be placed contiguous each abutment but for purposes of illustration such a pad has been shown L in detail as applied only to the abutment I2. The metal constituting the abutment I2 is shaped so that the sides I5 lie adjacent the sides of the shock absorbing device. As shown in Fig. 3 this device or pad comprises a rigid metal backing I6, layer or layers of shock absorbing material I1 and a face plate I8 of wear-resisting metal. Preferably both the backing I6 and the plate I8 are forgings thick enough to withstand the stresses without distorting the metal. The plate I8 is secured to the backing by rivets or other securing means I9 passing through all three portions of the device, the rivet heads being countersunk in the backing and in the plate as shown, permitting relative movement between the backing and plate along the Shanks of the rivets.

The sides I5 may be close enough to at least two opposite sides of the shock absorbing material I1 so as to limit any lateral expansion of material under compressive stress and thus reduce to some extent the amount of distortion to The abutments and frame constitute f which the pad may be subjected. In order to reduce the extent of distortion vtransversely of the material I1, that is longitudinally of the train. the securing means I9 are placed under an initial tension which imposes4 an initial compression upon the material I1. Thedegree of initial compression need not be any critical amount but preferably-it is such that loads lessthan 1000 pounds per square inchv are not adapted to compress the material I1'in a direction parallel to the shank of the securing meansy I9. An advantage of such initial1compression resides in the fact that not only is the material compressed under draft stress to asmall amount but the reaction from such compressionis also'limited to ja small amount by the slecuringmeans I9. The reduction -of movements longitudinally of the train aid in taking up While Vthe material slackwas quicklyl as possible. I1 `may be of rubber of `a "type which is not very. live, other equivalent and well known materials may be used. A preferred material includes layers of woven cotton fabric or canvas impregnated with a rubber-like adhesive and having layers of rubber or rubberlike material between them which are relatively thin compared to the thickness, of the fabric plies. Both the material for impregnation of the fabric and the interposed layers may be of rubber or rubber-like material. An advantage of having a rubber or rubber-like material very thin between the plies of canvas resides in the fact that such a shock absorbing pad is much less live than ordinary rubber and slow in re-coil so that the re-coil of the shock absorbing material does not aid so much in rebound of the draft gear after impact. Limiting the lateral expansion of the material I1 under heavy compression may assist in limiting the amount of yield. While the backing I6 and the plate I8 have been described as being preferably forgings, where the thickness of these plates is adequate, castings might be used.

In Figs. 4 to 6 is shown another embodiment of the shock absorbing device comprising a back- I ing or holder plate 20, laminated shock absorbing material 2l and a plate 22, the backing and plate being held together by rivets or other securing means' 23, the heads of which are preferably countersunk in the plates. 'Ihe plate 22 i'lts into a countersunk recess in the backing 20 with only a small lateral clearance as shownv in these figures. Slightly more lateral clearance is provided for the material 2l. Here again, however, the pad-is under an initial compression preferably high enough not to cause substantial reducto about 1000 pounds per square inch of area.'

. rial and passing through the plates and mate- The flanges of the backing 20 are substantially rigid. In Fig. 6 the lateral clearance between the edges of the shock absorbing material andk the countersunk faces of the surrounding flanges may be reduced so that the shock absorbing material is substantially contiguous these flanges. In Fig. 1 the edges of the material I? may or Amay not be contiguous the sides l5 for the purpose of limiting the spreading of the pad materialI under stress.

We claim:

I, 1. The combination in a railroad car draft gear having spaced abutments for taking draft `and buffer thrusts, of a cushioned follower Idevice between a portion of the gear and one of vsaid abutments, said cushioned device comprising a holder plate in which cushioning material is countersunk to a substantial depth, a second ,plate within the countersunk portion of the -holder plate and overlying said cushioning material, and headed securing means passing through Athe holder plate, cushioning material :and second plate, with the heads of `said securing means Ycountersunk in at least one of said plates, said securing means being under tension when said ldeviceis -not receivingthrusts, whereby said cushioning material is under an initial compression, said second plate beingvmovable on the securing means relative to the holder plate.

rial, said clamping means being headed and `ments comprising a holder in which cushioning material is countersunk to a substantial depth,

a plate within the countersunkportion of the holder and overlying said cushioning material, and headed securing means passing through the holder, cushioning material and plate, with the heads of said securing means countersunk in both the holder and plate, said plate and holder each being thicker than said cushioning material, the edge portion of the holder on each side of the countersunk areaV being wider than the thickness of said plate, the clearance between said plate and the countersunk sides being smaller kthan the clearance between the cushioning material and said countersunk sides whereby the lateral expansion of the cushioning material is guided by said plate and undue distortion prevented.

THOMAS FRANCIS DWYER, JR.

DAVID`W. GRAY. 

